I have a question about the increasing behavior of entropy. Suppose we heat a metal (Take for instance Fe) till it radiates energy and then put it in space (No medium). So the metal radiates energy in electromagnetic waves which decreases the entropy of the metal (Due to decrease in internal energy of metal. I hope so ).On the other hand the E.M. waves will keep traveling in space (no medium.It might get absorbed by other objects but still space is quite large?)(The space will be the dump for this energy).So the net entropy change will be a decrease (due to decrease in the system (Fe metal)).But second law of thermodynamics states that entropy always increases for irreversible change. Where have I gone wrong? Help will be appreciated.Thank you .